Antibodies to CD150 can inhibit T_H2 polarization in an IFN-γ–dependent fashion.

CD4 T cells were stimulated with anti-CD3 under T_H1 or T_H2 conditions with or without the addition of anti-CD150 antibodies for 72 hours. Following a rest period of 48 hours in IL-2 (50 U/mL) cells were restimulated with anti-CD3 (1 μg/mL plate bound) and IL-2 (50 U/mL). In panels A and C, T_H2 priming was performed with IL-4 and anti–IL-12; in panels B and D, T_H2 priming was performed with IL-4 and anti–IFN-γ. Primary stimulation conditions are indicated (1°) on the x-axis. Concentrations of IFN-γ and IL-4 in culture supernatants were assayed by ELISA as outlined in “Materials and methods.” Bars represent the means of triplicate measurements.